Test tube holding device



FIG. 1 is a perspective view of a test tube holding device in an open configuration according the present invention.

FIG. 2 is a front view of the test tube holding device of FIG. 1.

FIG. 3 is a rear view of the test tube holding device of FIG. 1.

FIG. 4 is a left-side view of the test tube holding device of FIG. 1.

FIG. 5 is a right-side view of the test tube holding device of FIG. 1; and,

FIG. 6 is a top view of the test tube holding device of FIG. 1.

The broken lines show portions of the test tube holding device that form no part of the claimed design. 

CLAIM We claim the ornamental design for a test tube holding device, as shown and described. 